1. Field of the Invention
The present invention relates to air intake for carburetors, and more particularly, to an air intake scoop for a motorcycle carburetor which inserts into the carburetor and fits within the air filter housing.
2. Description of the Prior Art
In motorcycle carburetors mounted with a horizontal opening, such as Harley Davidson models of 883 cc, 1400 cc, and 80 ci depending on which motor combination, pipes, cam with valve overlap, a problem that can occur in some instances is that a gas mist comes out of the carburetor when accelerating allowing gas to saturate the air filter with a gas mist and then the gas will drip down the side of the motorcycle causing gasoline odors, possible paint damage, stains, and a potential fire hazard.
Prior art air intakes in most instances do not address the problem of gas misting from the carburetor.
Prior art intakes do not direct the airflow into the carburetor from inside the air filter area with an enclosed shroud forcing the air into the carburetor improving the performance of the motor.
U.S. Pat. No. 4,592,316, issued Jun. 3, 1986 to Shiratsuchi, et al., describes an air funnel assembly extending between an air inlet assembly and one or more carburetors on a two-wheeled vehicle. The air funnel assembly includes an elastic air funnel and an air funnel cover. The funnel and funnel cover are affixed to the carburetor or carburetors and extend in spaced relation towards the air inlet assembly. The components may be fixed to the carburetors by means of one or more clamp rings, may be additionally joined together by projections from the elastic funnel which are retained in holes in the rigid cover. A radially interlocking arrangement may be employed at the inlet from the air inlet assembly to retain the funnel thereto.
U.S. Pat. No. 5,868,808, issued Jan. 9, 1999 to Henderson, shows a carburetor air intake velocity stack engagable with a carburetor inlet, that has a cylindrical throat section having first and second ends. The first end is adapted to be coupled to the carburetor, while the second end is open to the air. A shaped, mesh filter having an effective open area which exceeds the open area of the velocity stack by at least about 50%, is located within said air intake velocity stack. The filter has a cylindrically formed flange member which is trapped between said air intake velocity stack and the carburetor.
U.S. Pat. No. 6,371,068, issued Apr. 16, 2002 to Taylor, claims a modified air intake mechanism for an internal combustion engine. The air intake mechanism includes an air passageway that contains a fixed vane located in a plane that is parallel to the air flow within the passageway. More specifically, the vane is stationary and is located in the air horn or the air intake passageway of the cylinder head.
U.S. Pat. No. 4,066,720, issued Jan. 3, 1978 to Carter, provides an improved carburetor air intake velocity stack for maximizing the quantity of air delivered to a carburetor. An air intake velocity stack is adapted to be coupled to the air inlet of a carburetor, the surface of the air intake stack substantially eliminating turbulence at the air intake velocity stack as well as increasing the density of air being input to the carburetor. The curvature of the intake stack provides for substantially laminar flow of the input air, the laminar flow being undisturbed by the shape of the input path.
U.S. Pat. No. 5,549,085, issued Aug. 27, 1996 to Endrigo, discloses an insert device for smoothing air flow from air filters to carburetors. The device is suitable for turning an air stream from an intake air passageway, which is directed inwardly along a plane from a periphery towards a center to a fuel/air mixing chamber having an annular downwardly flowing mixing passageway with a longitudinal axis at the center. The insert device includes a first end adapted to be operably located concentrically with the annular fuel/air passageway, and a second end opposite the first end. The first and second ends have a central axis extending therebetween. The second end has a center and an upper wall extending outwardly therefrom. A peripheral wall of diminishing outside diameter begins at a point spaced outwardly near the center of the second end and extends smoothly to a point of minimum diameter. From the point of minimum diameter, concave shaped subwalls of slightly increasing size extend downward to the first end. In an alternate embodiment, from the point of minimum diameter, a single peripheral wall of increasing diameter extends to and connects with the first end.
What is needed is a means for preventing gas from misting out of horizontally oriented motorcycle carburetor openings.
What is also needed is a means to prevent the air from flowing past the carburetor inlet. Air needs to be funneled directly into the carburetor, which improves performance.
An object of the present invention is to provide an air intake scoop to draw a strong flow of air into a motorcycle carburetor having a horizontal opening to force the flow of air into the carburetor and prevent the gas mist from exiting the carburetor.
Another object of the present invention is to provide a small-sized air flow scoop to fit onto the motorcycle carburetor and under the air filter.
One more object of the present invention is to provide an inexpensive air intake scoop molded preferably of polyurethane or other gas and oil resistant plastic or rubber.
An additional object of the present invention is to provide an air intake scoop which has 90 degree airflow movement to take in air from the forward direction of travel of the motorcycle and send it 90 degrees into the side mounted mouth of the carburetor.
A further object of the present invention is to provide a rubber or plastic air intake scoop which may be easily adapted to fit a variety of different sizes of carburetors and filters.
Yet one more object of the present invention is to provide a cover for the air filter with a movable lid over a forward opening in the cover to admit a substantial flow of air into the air scoop with the lid open on days when it is not raining and with the lid closed to prevent water from entering the carburetor on rainy days.
In brief, a sleeve elbow with a 90 degree bend is molded of polyurethane or other gas and oil resistant plastic or rubber. A circular opening fits with a tight friction fit inside the mouth of the carburetor which opens to the side of the motorcycle. A rim recessed from the circular opening acts as a stop and contacts the rim around the mouth of the carburetor.
The other end of the elbow faces in the forward direction of travel of the motorcycle to scoop in the air. The front facing portion of the elbow is cut away to create a larger scoop area extending from the rim to the outer tip of the elbow. A ridge protrudes along the inside centerline of the back surface of the elbow from the circular opening to the front edge of the scoop, the ridge acting as a vortex generator to assist in directing air flow into the mouth of the carburetor.
The air filter fits over the air intake scoop and bolts onto the carburetor backing plate in a normal fashion. A cover for the air filter is preferably bowl shaped and attractively chrome coated and fits onto the air filter with a single center bolt. A sliding lid in a front portion of the cover opens to admit air through a front opening in the cover in a strong current into the air scoop on clear days and closes to prevent water from entering the carburetor on rainy days.
An advantage of the present invention is that it funnels air directly into the carburetor, which improves performance while the vehicle is in motion.
Another advantage of the present invention is to provide a means to maintain a gasoline free air filter.
Another advantage of the present invention is to provide a means to prevent gas from dripping down from the carburetor.